Gear casing

ABSTRACT

An improved two-piece gear casing for housing a gear train associated with the traction motor supporting-frame of a locomotive or other vehicle comprises two integrated substantially identical half-casings molded of reinforced plastic material in combination with load-bearing metal straps adapted to embrace the half-casings in a manner to secure them together on the supporting frame of a traction motor and to lock each halfcasing from lateral displacement relative to its load-bearing strap.

United States Patent Hanson et al.

1451 Apr. 17,1973

[54] GEAR CASING FOREIGN PATENTS OR APPLICATIONS 1 lflvemorsl g g a ggf i 478,104 11 1915 France ..105/140 exan er nnic enview, of Primary ExaminerCharles J. Myhre [73] Assignee: NL Industries, Inc., New York, NY. Assistant E.xaminerF D. Shoemaker [22] Filed: Sept 27 1971 Att0mey--Robert L. Lehman et al.

An improved two-piece gear casing for housing a gear [21:] 74/609F, 1l)5/1l/gg train associated with the traction motor Supporting g 606 frame of a locomotive or other vehicle comprises two 6 6 integrated substantially identical half-casings molded of reinforced plastic material in combination with l 56] References Cited load-bearing metal straps adapted to embrace the halfcasings in a manner to secure them together on the UNITED STATES PATENTS supporting frame of a traction motor and to lock each 1,063,676 6/1913 Grady ..74/609 lfing from later l displacement relative to its 1,048,328 12/1912 Maize..... load-bearing strap.

954,038 4/l9l0 Mason 1,292,265 1/1919 Cramer ..74/609 14 Clains, 7 Drawing Figures i6 7 r 44 40 /7 J7 :1 3

a 4 r 24 7 j l 1' 1 \l|1 i w W1 35 I [f I W H 3} r": 5 27 l r 1 27 I 25/ i7 PATENTEI] APR 1 7 I973 SHEET 1 BF 3 PATENTEDAPR 1 1 I915 3'. 727. 483

SHEET 2 [1F 3 SHEET 3 0F 3 GEAR CASING BACKGROUND OF THE INVENTION The invention relates generally to gear casings or housings and more especially to the type of gear casing adapted to be mounted on the traction motor supporting-frame of a locomotive for housing the gear train associated therewith. Heretofore these gear casings have been fabricated of heavy steel plate and hence have been extremely heavy as a consequence they are difficult to mount on or disassemble from the supportingframe. Moreover, these metal casings are expensive to manufacture and by reason of their bulk and hardness can easily effect a derailment in the event the casing is broken or otherwise inadvertently detached from its supporting-frame.

It is desirable therefore, to provide a gear casing which is of light weight construction yet resistant to breakage, puncture or cracking; which is relatively inexpensive to manufacture; which is easy to assemble or disassemble and which provides an effective seal against loss of lubricant for the gear train which it houses.

SUMMARY OF INVENTION The present invention relates to an improved twopiece gear casing which overcomes many of the disadvantages of earlier gear casings, the improved twopiece gear casing of this invention being characterized by two integrated substantially identical half-casings each molded of a reinforced plastic material in combination with load-bearing metal straps adapted to embrace each half-casing in a manner to hold the half-casings together on a supporting frame member, the metal straps and half-casings having complimentary retaining means for preventing lateral displacement of the halfcasings relative to their respective load-bearing straps. Moreover, to insure a tight substantially rigid joint between the half-casings the opposing edges of the halfcasings are formed with molded tongues and grooves, respectively, adapted to interlock when the two-half casings are secured together; and with semi-circular cut-outs so arranged that when the half-casings are joined together to form an integrated gear casing the semi-circular cutouts define circular apertures for accommodating one or more gear shafts of a gear train housed within the casing, each circular aperture, so formed, being provided with circumferential sealing means for minimizing loss of gear lubricant from the gear casing and loss of lubricating oil from the axle support bearing.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of the improved two-piece gear casing including the combined load-bearing metal straps as viewed from the wheel side of the casing.

FIG. 2 is a side elevation of the gear casing as viewed from the traction motor side.

FIG. 3 is an enlarged end elevation in section of the gear casing on line 3-3 of FIG. 2.

FIG. 4 is an enlarged fragmentary elevation in section of the gear casing on line 4-4 of FIG. 2.

FIG. 5 is an enlarged end elevation in section of the gear casing on line 5-5 of FIG. 2.

FIG. 6 is an enlarged vertical section of the upper half-casing of FIG. 1 showing details of the locking elements of the load-bearing strap and half-casing whereby the latter is prevented from moving laterally with respect to its strap; and

FIG. 7 is an enlarged phantom view, in perspective, of the gear casing of this invention secured to the traction motor supporting-frame by the load-bearing metal straps.

Referring to FIGS. 1 and 2 the two-piece plastic gear casing is indicated generally by the numeral 10 and comprises two substantially identical half-casings 11 and 12, sometimes referred to hereinafter as the upper half-casing and the lower half-casing, respectively. Each half-casing comprises a single molded plastic member having two substantially parallel side walls and an integral end wall. Referring particularly to FIG. 3 the side walls and end wall of the upper half-casing are identified by numerals 110, 111, and 112 respectively while the corresponding side walls and end wall of the lower half-casing are identified by numerals 120, 121 and 122 respectively. Each half-casing is molded of a suitable reinforced plastic material which, for purposes of illustration, may be a fiber glass composition composed of an epoxy-novolack resin reinforced with fiber glass fabric. It will be understood, however, that other reinforced plastics having good molding characteristics and capable of forming light weight but strong molded articles may be used, as for example glass or other fiber impregnated polyester or polycarbonate resins, and are contemplated within the scope of the present invention.

The two half-casings are adapted to be assembled together to form a single integrated gear casing by engaging the spaced parallel free edges, sometimes referred to as the opposing edges, of one half casing with the opposing edges of the other half casing. To this end and in the interest of providing relatively simple means for forming a tight and rigid joint between the two half-casings the opposing edges of one half-casing are provided with molded grooves Ill-13, see FIG. 4, while the opposing edges of the other half-casing are provided with molded tongues 14-44 adapted to interlock with the grooves 13l3. The particular tongue and groove configuration shown in. FIG. 4 is especially desirable since it insures a joint of maximum strength and rigidity but it will be understood that other configurations may be used and are contemplated within the scope of the present invention.

As shown in FIG. 2 the two-piece gear casing used to illustrate but not limit the present invention is designed to enclose a gear train comprising a pinion drive gear 15 secured to the drive shaft 16 of a traction motor;

.and a driven gear 17 secured to shaft 18. As shown in FIG. 7 the latter constitutes the axle of a flanged traction wheel 20 of a locomotive or similar rail vehicle and extends through axially aligned apertures formed in both sides of the gear casing, whereas the shaft 16 of pinion gear 15 extends into the gear casing through a single aperture in one side only of the gear casing.

FIG. 2 shows the traction motor side of the gear casing which is provided with apertures for accommodating shaft 16 of the pinion gear 15 and the axle 18 each aperture being formed by providing complimentary semi-circular cutouts 2121 and 2222 respectively in the opposing edges of each half-casing, the diameters of the semi-circular cutouts being coincident with the corresponding free edges of their respective half-casings. Similarly semi-circular cutouts 23-23 are formed in the opposing edges of the half-casings on the wheel side of the assembled casing, see FIG. 1, to provide a circular aperture through which the axle 18 extends to support the flanged wheel 20, as shown in FIG. 7.

The two-piece gear casing is adapted to contain a lubricant for lubricating the gear train enclosed therein, and hence suitable seals are provided circumscribing the aforesaid apertures to minimize loss of lubricant from the gear casing. Referring particularly to FIGS. 3 and the traction motor side of the assembled half-casings is provided with integrally molded semicircular flanges 24-24 circumscribing the respective semi-circular cutouts 21-21, said semi-circular flanges 24-24 being arranged to overlie the hub 25 of the driven gear 17 and the axle bearing 26 carried by the traction motor; and semi-circular flanges 27-27 (See FIG. 5) being arranged to overlie a traction motor flange 28 of drive shaft 16. Similarly semi-circular flanges 29-29 are formed on the wheel side of the gear casing circumscribing the respective cut-outs 23-23 said flanges 29-29 being arranged to overlie the hub 30 of the locomotive wheel. Each of the aforementioned flanges has one or more grooves molded in its inner wall to accommodate sealing-means, indicated generally at 31, said sealing means being in the form of semi-circular strips of felt, sheet steel bonded felt, oilresistant rubber-fabric material and the like. As shown 'in FIGS. 3 and 5 each of the semi-circular flanges 24 has three grooves 32 molded in its inner wall; the flanges 27 with one groove 33; and the flanges 29 with one groove 34 for accommodating sealing felts 31. It should be noted, however, that the middle grooves 32 of semi-circular flanges 24-24 do not have sealing felts and that the lower groove 32 is provided with a drain hole 32a. This is provided to allow any gear grease from the gear casing or any lubricating oil from the axle support bearing to drain on to the right of way thus obviating migration of any bearing lubricating oil into the gear case or migration of the gear lubricant into the axle support bearing.

Consistent with the objects of providing a relatively light weight, tough gear casing which can be readily mounted on or removed from the traction motor frame, the assembled half-casings are combined with fastening means which serve to clamp the two half-casings together on a supporting frame member, as for example the supporting lugs 35'of the traction motor, as shown in FIG. 7; and to absorb and transmit any operating loads to the supporting frame. Referring in particular to FIG. 6, which is a vertical section of the upper half-casing 11, the fastening means is shown as comprising a metal strap 36 designed to embrace the endwall 112 of the half-casing the strap 36 being reinforced at each extremity by a relatively heavy shoe 37 having a bolt hole 38 therein. A similar metal strap 36 is adapted to embrace the end wall of the lower half-casing. The bolt holes 38 in the shoes 37 at the extension of each strap,

are adapted to be aligned with holes in corresponding lugs 35-35 of the traction motor frame to receive a bolt by which the corresponding extremities of each strap 36 are bolted to the traction motor. In this manner any operating loads applied to the integrated gear casing through the gear shafts are transferred to the straps 36 and hence absorbed by the motor frame.

In addition to serving as a relatively simple and convenient means for fastening the half-casings together on the traction motor frame, and absorbing operating loads, the load-bearing straps 3636 are provided with retaining means designed to mutually engage with suitable retaining means on the end walls of the assembled gear casing to prevent lateral displacement thereof relative to the load-bearing straps 36-36. To this end the end wall of each half-casing is provided adjacent one extremity thereof with an upstanding knob 39 adapted to engage in a dimple 40 formed in the underside of its respective load-bearing strap 36. At the opposite extremity of each end wall is a circular aperture 41 the rim of which is punched outwardly to form an upstanding circular flange 42 the diameter of the flange 42 being such that it fits relatively snugly in an aperture 43 of the corresponding strap 36. Thus when the loadbearing straps 36-36 are combined with the respective half-casings to hold them together and form an integrated gear casing engagement of the knobs 39-39 with their dimples 40-40 and the flanges 42-42 in their respective apertures 43-43 effectively prevents any lateral movement of the integrated gear casing relative to the supporting straps 36. The flanged apertures 41 also provide access to the interior of the gear casing whereby a lubricant can be added as desired, each flanged apertures 41 having a closing cap 44 suitably designed to be locked in place.

From the foregoing description and the drawings it is clear that the present invention provides an improved two-piece gear casing characterized by a molded plastic body consisting of two substantially identical molded half-casings joined together along their opposing edges by tongue and groove joints, in combination with load-bearing metal straps adapted to embrace each half-casing in a manner to hold the latter together and form an integrated gear casing secured to the frame of a traction motor, the metal straps and gear casing being mutually locked together to prevent lateral displacement of the casing relative to the loadbearing straps.

While the invention has been illustrated by the specific embodiment described above it will be understood that the latter is not limiting of the scope of the invention and that the invention may be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention.

We claim:

1. A two-piece plastic gear casing adapted to be secured to a frame-member and house elements of a gear train said gear casing comprising in combination; two integrated substantially identical molded half-casings of reinforced plastic material, said intergrated halfcasings having opposing edges provided with molded interlocking means, a circular aperture in at least one of the walls of said integrated half-casings for accommodating the shaft of a gear train housed therein, sealing means circumscribing the periphery of said aperture and loadbearing fastening means comprising metal straps constructed and arranged to embrace and hold said half-casings together in integrated relationship on said frame-member and to retain said gear casing against displacement relative to said metal straps.

2. A two-piece plastic gear casing according to claim 1 wherein said metal straps and said integrated halfcasings are constructed with mutually engaging elements, respectively, to retain said gear casing against lateral displacement relative to said metal straps.

3. A two-piece plastic gear casing adapted to be secured to a frame-member and house elements of a gear train said gear casing comprising in combination: two integrated, substantially identical, molded half-casings of a reinforced plastic material, said integrated half-casings having opposing edges provided with interlocking means, oppositely disposed semi-circular cutouts in the opposing edges, respectively, of said halfcasings, the semicircular cut-out of one half-casing being arranged to form a substantially circular aperture with the semicircular cut-out of the other half-casing for accommodating a gear shaft when said half-casings are secured together on said frame member, molded flanges circumscribing said semicircular cut-outs, sealretaining grooves molded in the inner walls of said molded flanges, sealing means arranged to be retained in the molded seal-retaining grooves of said molded flanges to form seals between the said flanges and elements of said gear train, load-bearing fastening means constructed and arranged to hold said half-casings together in integrated relationship on said framemember and retaining means constructed and arranged on said fastening means and said half-casings, respectively, to mutually engage when said half-casings are held together by said fastening means in integrated relationship on said frame member.

4. A two-piece plastic gear casing adapted to be secured to the supporting-frame of a traction motor and house elements of a gear train driven thereby, said gear train including a motor driven pinion gear and a driven gear said driven gear having a hub and arranged to be secured on a shaft mounted in a sleeve bearing and carrying a traction wheel, said gear casing comprising in combination: two integrated, substantially identical, molded half-casings of a reinforced plastic material, said integrated half-casings having opposing edges provided with interlocking means, oppositely disposed semicircular cut-outs in the opposing edges, respectively, of said half-casings, the semicircular cut-out of one half-casing being arranged to form a substantially circular aperture with the semicircular cut-out of the other half-casing for accommodating a gear shaft when said half casings are secured together on said supporting-frame; molded flanges circumscribing said semicircular cut-outs, a plurality of seal retaining grooves molded in the inner walls of said molded flanges, sealing means arranged to be retained in the inner-most and outer-most seal-retaining grooves respectively of said molded flanges to form seals between said flanges and the hub and sleeve bearing, respectively, of said driven gear, load-bearing fastening means constructed and arranged to hold said half-casing together in integrated relationship on said supporting-frame and retaining means constructed and arranged on said fastening means and said half-casings, respectively, to mutually engage when said half-casings are held together by said fastening means in integrated relationshig') on said frame member.

. A two-piece plastic gear casing adapted to be secured to the supporting-frame of a traction motor according to claim 4 wherein an intermediate seal retaining groove of said molded flanges has an aperture in its bottom half for discharging lubricants therefrom.

6. A two-piece plastic gear casing according to claim 3 wherein said interlocking means comprises molded tongues and grooves in the opposing edges respectively, of said half-casings.

7. A two-piece plastic gear casing according to claim 3 wherein the sealing means comprises lubricated packing material arranged to be retained in said molded seal-retaining grooves.

8. A two-piece plastic gear casing according to claim 3 wherein each half-casing is substantially U-shaped in cross section and comprises a single molded member having two spaced parallel side walls and an end wall.

9. A two-piece plastic gear casing according to claim 8 wherein said load-bearing fastening means comprises metal straps arranged to embrace the end walls respectively, of said half-casings, said straps being constructed and arranged to be secured at their opposite ends to said frame member.

10. A two-piece plastic gear casing according to claim 9 wherein the retaining means comprises protuberances at the opposite ends respectively of the end wall of each half-casing and oppositely disposed recesses at opposite ends respectively of each metal strap, said protuberances being arranged to mutually engage in the recesses of said straps when said half-casings are held together by said metal straps on said frame member.

11. A two-piece plastic gear casing according to claim 9 wherein the opposite ends, respectively, of each of said metal straps is provided with an integral shoe having an aperture therein whereby said straps may be bolted to said frame member.

12. A two-piece plastic gear casing according to claim 10 wherein the recess at one end of each metal strap comprises an aperture and the protuberance at the corresponding end of each half-casing comprises an upstanding flange circumscribing an aperture in its end wall said upstanding flange being arranged to make a snug fit in the aperture in the corresponding end of its respective metal strap.

13. A two-piece plastic gear casing according to claim 7 wherein semicircular cutouts are provided in opposing edges of both walls of each half-casing and in transverse alignment whereby two substantially circular apertures are formed in opposite walls of the assembled gear casing for accommodating a gear shaft.

14. A two-piece plastic gear casing according to claim 13 wherein in addition to the two transversally aligned apertures in opposite walls of the assembled gear casing a second circular aperture is formed in one of the walls of the gear casing for accommodating a second gear shaft, said second circular aperture being formed by providing additional semicircular cut-outs in opposing edges of corresponding walls of said half-casings. 

1. A two-piece plastic gear casing adapted to be secured to a frame-member and house elements of a gear train said gear casing comprising in combination; two integrated substantially identical molded half-casings of reinforced plastic material, said intergrated half-casings having opposing edges provided with molded interlocking means, a circular aperture in at least one of the walls of said integrated half-casings for accommodating the shaft of a gear train housed therein, sealing means circumscribing the periphery of said aperture and loadbearing fastening means comprising metal straps constructed and arranged to embrace and hold said half-casings together in integrated relationship on said frame-member and to retain said gear casing against displacement relative to said metal straps.
 2. A two-piece plastic gear casing according to claim 1 wherein said metal straps and said integrated half-casings are constructed with mutually engaging elements, respectively, to retain said gear casing against lateral displacement relative to said metal straps.
 3. A two-piece plastic gear casing adapted to be secured to a frame-member and house elements of a gear train said gear casing comprising in combination: two integrated, substantially identical, molded half-casings of a reinforced plastic material, said integrated half-casings having opposing edges provided with interlocking means, oppositely disposed semi-circular cut-outs in the opposing edges, respectively, of said half-casings, the semicircular cut-out of one half-casing being arranged to form a substantially circular aperture with the semicircular cut-out of the other half-casing for accommodating a gear shaft when said half-casings are secured together on said frame member, molded flanges circumscribing said semicircular cut-outs, seal-retaining grooves molded in the inner walls of said molded flanges, sealing means arranged to be retained in the molded seal-retaining grooves of said molded flanges to form seals between the said flanges and elements of said gear train, load-bearing fastening means constructed and arranged to hold said half-casings together in integrated relationship on said frame-member and retaining means constructed and arranged on said fastening means and said half-casings, respectively, to mutually engage when said half-casings are held together by said fastening means in integrated relationship on said frame member.
 4. A two-piece plastic gear casing adapted to be secured to the supporting-frame of a traction motor and house elements of a gear train driven thereby, said gear train including a motor driven pinion gear and a driven gear said driven gear having a hub and arranged to be secured on a shaft mounted in a sleeve bearing and carrying a traction wheel, said gear casing comprising in combination: two integrated, substantially identical, molded half-casings of a reinforced plastic material, said integrated half-casings having opposing edges provided with interlocking means, oppositely disposed semicircular cut-outs in the opposing edges, respectively, of said half-casings, the semicircular cut-out of one half-casing being arranged to form a substantially circular aperture with the semicircular cut-out of the other half-casing for accommodating a gear shaft when said half casings are secured together on said supporting-frame; molded flanges circumscribing said semicircular cut-outs, a plurality of seal retaining grooves molded in the inner walls of said molded flanges, sealing means arranged to be retained in the inner-most and outer-most seal-retaining grooves respectively of said molded flanges to form seals between said flanges and the hub and sleeve bearing, respectively, of said driven gear, load-bearing fastening means constructed and arranged to hold said half-casing together in integrated relationship on said supporting-frame and retaining means constructed and arranged on said fastening means and said half-casings, respectively, to mutually engage when said half-casings are held together by said fastening means in integrated relationship on said frame member.
 5. A two-piece plastic gear casing adapted to be secured to the supporting-frame of a traction motor according to claim 4 wherein an intermediate seal retaining groove of said molded flanges has an aperture in its bottom half for discharging lubricants therefrom.
 6. A two-piece plastic gear casing according to claim 3 wherein said interlocking means comprises molded tongues and grooves in the opposing edges respectively, of said half-casings.
 7. A two-piece plastic gear casing according to claim 3 wherein the sealing means comprises lubricated packing material arranged to be retained in said molded seal-retaining grooves.
 8. A two-piece plastic gear casing according to claim 3 wherein each half-casing is substantially U-shaped in cross section and comprises a single molded member having two spaced parallel side walls and an end wall.
 9. A two-piece plastic gear casing according to claim 8 wherein said load-bearing fastening means comprises metal straps arranged to embrace the end walls respectively, of said half-casings, said straps being constructed and arranged to be secured at their opposite ends to said frame member.
 10. A two-piece plastic gear casing according to claim 9 wherein the retaining means comprises protuberances at the opposite ends respectively of the end wall of each half-casing and oppositely disposed recesses at opposite ends respectively of each metal strap, said protuberances being arranged to mutually engage in the recesses of said straps when said half-casings are held together by said metal straps on said frame member.
 11. A two-piece plastic gear casing according to claim 9 wherein the opposite ends, respectively, of each of said metal straps is provided with an integral shoe having an aperture therein whereby said straps may be bolted to said frame member.
 12. A two-piece plastic gear casing according to claim 10 wherein the recess at one end of each metal strap comprises an aperture and the protuberance at the corresponding end of each half-casing comprises an upstanding flange circumscribing an aperture in its end wall said upstanding flange being arranged to make a snug fit in the aperture in the corresponding end of its respective metal strap.
 13. A two-piece plastic gear casing according to claim 7 wherein semicircular cutouts are provided in opposing edges of both walls of each Half-casing and in transverse alignment whereby two substantially circular apertures are formed in opposite walls of the assembled gear casing for accommodating a gear shaft.
 14. A two-piece plastic gear casing according to claim 13 wherein in addition to the two transversally aligned apertures in opposite walls of the assembled gear casing a second circular aperture is formed in one of the walls of the gear casing for accommodating a second gear shaft, said second circular aperture being formed by providing additional semicircular cut-outs in opposing edges of corresponding walls of said half-casings. 